Urinary myelin figures in gentamicin nephrotoxicity.

Abstract

The nephrotoxicity of gentamicin is associated with formation of myelin figures within the proximal convoluted tubules of experimental animals and man. By electron microscopy, the authors studied urinary sediments of patients who were treated with gentamicin to detect the occurrence of myelin figures. All three patients who had renal impairment and were treated with gentamicin had numerous urinary myelin figures. By contrast, myelin figures were not observed in urinary sediments of four patients who had no renal impairment despite gentamicin therapy, or nine patients who had no renal impairment and did not receive gentamicin therapy. Occasional myelin figures were detected in a urinary sediment of one of eight patients who had renal impairment and no gentamicin therapy. When the urinary sediments of patients who had gentamicin nephrotoxicity were compared with those of patients with Fabry disease, morphologic differences between the myelin figures of the two groups were detected. The study demonstrates the presence of myelin figures in urines of patients with acute renal failure receiving gentamicin, and suggests that the finding of these myelin figures within urine samples may contribute to the diagnosis of gentamicin-induced nephrotoxicity.